Differential compensating float



Sept. 30, 1930. F. E. LEAHY DIFFERENTIAL'COMPENSATING FLOAT Filed July2, 1926 p Inventor WM 2? By 30 to the producer chamber.

Patented Sept. 30, 1930 entree stares PATENT OFFIQE FRANK E. LEAHY, OFPITTSBURGH, PEIINSYLVANIA, AFSSIGNOR TO REPUBLIC FLOW METERS 00., OFCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS DIFFERENTIAL COMPENSATINGFLOAT Application filed July 2,

This invention relates to afloat arranged to be actuated by diflerentialgas pressure and has for its object the provision for such a float inwhich the movement may be damped and in which the amount of damping maybe 15 embodiment of the invention as applied to a gas producer furnace.It will be understood that the illustration is given by way of exampleand that the float is applicable to many purposes other than that ofregulating 20 a gas producer, and that the construction of the floatitself may be varied without departing from the spirit and scope of theinvention.

In the drawing, the numeral designates as a gas producer having a blower11 to which steam is supplied by means of a steam line 12. The blower 11is of the injector type by means of which a jet of steam aspirates theair and furnishes a mixture of steam and air Instead of a steamaspirator, a turbo blower may be used as is done in many cases inconnection with gas producers. With either form of blower, the amount ofgas produced is a direct'function of 5 the air supplied and consequentlyof the steam supplied through the pipe 12. The gas is discharged fromthe producer 10 through a gas main 13 in which it is desirable tomaintain a constant gas pressure. To

to accomplish this result, a pipe 14 communicates with the interior ofthe main 13 and has its opposite end 15 opening within a bell float 16which is inverted in a body of liquid 17 contained in a vessel 18. Thefloat 16 is as connected by a link 19 with a lever arm 20 It will beseen that when the pressure de- 1926. Serial No. 120,113.

creases in the main 13, the float 15 will sink and tend to open thevalve 21 to supply more steam to the producer, thus causing more rapidproduction of gas and a consequent rise in pressure in the main. If thepressure becomes excessive in the main 13, the float 16 will be raisedtending to close thevalve 21, thus decreasing the supply of steam andreducing the rate of production and consequently the pressure in themain 13. It has been found that where a bell float is provided withstraight sides, the response to changes in pressure in the main 13 is sorapid that extreme variation in the steam flow is produced which giverise to faulty operation of the producer. In many cases, the amount ofsteam admitted incident to a drop in pressure is in excess of thatrequired to restore the pressure so that the pressure is raised abovenormal and the float goes to the opposite 6X- treme giving rise to ahunting operation of the float. To overcome these difliculties, thefloat 16 is provided with an internal chamber-22 formed by an inclinedannular wall 23 and an annular bottom 24. Communication between thechamber 22 and the chamber 17 is provided by restricted openings 25which may bein the form of perforations through the bottom 24, as shownin the drawing, or may be in the form of a slit in the side of the wall23, or any other suitable form. IVith this arrangement, it will be seenthat with any variation of the gas pressure, the body of liquid withinthe float will resist movement of the float until the liquid passesthrough the openings 25 to equalize the liquid level in the chambers 17and 22. This prevents sudden changes in the steam flow, gives moreuniform operation of the producer and avoids hunting of the float. I

In the drawing, the wall 23 is shown as inclined outwardly toward itsupper edge. With this arrangement, a less quantity of liquid passingthrough the perforations 25 will restore the liquid level when the'floatis depressed than is required whenthe float rises. This will permitquicker response to a decrease in the gas pressure than is permitted foran increase in the pressure. It will be apparent that the dilferencebetween the quickness of the response for up and down movement of thebell may be regulated by changing the angle of the wall 23 and thecondition may be reversed by inclining the wall inwardly instead ofoutwardly toward its upper edge, the amount of movement of the valve 21for a given variation in gas pressure may be adjusted by changing thelength of the lever arm 20. The damping effect may be regulated byregulating the size of the perforations 25.

In addition to the float 16, a second float 26 supported on liquid 27 ina vessel 28, similar to the support for the float 16, may be provided.The pipe 29 is connected with the pipe 14 and opens beneath the float26. The float 26 is provided with a damping chamber 30 similar to thedamping chamber 22 but the wall of the chamber 30 may be straightinstead of inclined to give equal sensitiveness in both directions. Thefloat 26 is connected to a pivoted pointer 31 which travels along ascale 32 and may be provided with a weight or other arrangement 33 fortending to hold the pointer in a zero position. By this means, apressure gage is provided which will indicate the pressure in the main13.

I claim 1. A pressure responsive device of the class describedcomprising a receptacle for a liquid, a partly submerged invertedbell-shaped member adapted to move up and down in said receptacle, saidbell-shaped member having an imperforate top and side walls and anextension on said walls extending inwardly and then upwardly therefrom,the submerged portion of the bell-shaped member having openingstherethrough and said upwardly extending portion being shaped so thatthe cross-sectional area of the space enclosed thereby varies from thelowermost part of said enclosed space to the top of said enclosed space,the upper edge of said upwardly extending portion terminating above theliquid level in said receptacle to prevent any liquid from flowingbetween said receptacle and said bell-shaped member except through saidopenings.

2. A pressure responsive device of the class described comprising areceptacle for a liquid, a partly submerged inverted bell-shaped memberadapted to move up and down in said receptacle, said bell-shaped memberhaving an imperforate top and side walls and an ex tension on said wallsextending inwardly and then upwardly therefrom, the submerged portion ofthe bell-shaped member having openings therethrough and said upwardlyextending portion being shaped so that the cross-sectional area of thespace enclosed thereby increases from the lowermost part of saidenclosed space to the top of said enclosed space, the upper edge of saidupwardly extending portion terminating above the liquid level in saidreceptacle to prevent any liquid from flowing between said receptacleand said bell-shaped member except through said 0 enings.

3. device as claimed in claim 1, in which the bell-shaped member is soconstructed that less movement thereof is required to bring the liquidto the desired level when the bellshaped member is at the lowermostportion of its travel than when it is at its uppermost portion.

4. A pressure responsive device of the class described comprising areceptacle for a liquid, a partly submerged bell-shaped member adaptedto move up and down in said receptacle, said bell-shaped member havingan imperforate top and parallel side walls and an extension on saidwalls extending inwardly and then upwardly therefrom, the submergedportion of the bell-shaped member having openings therethrough and theupper edge of said upwardly extending portion terminating above theliquid level in said receptacle to prevent any liquid from flowingbetween said receptacle and said bell-shaped member except through saidopenings.

In testimony whereof I have signed my name to this specification on this21st day of June, A. D. 1926.

FRANK E. LEAHY.

